"Bruno Luong" <b.luong@fogale.findmycountry> wrote in message <kcd1lg$6u4$1@newscl01ah.mathworks.com>...> "Matt J" wrote in message <kcd0g0$34t$1@newscl01ah.mathworks.com>...>> > Just like sum([]), prod([]), this result is no exception so to be documented separately.==============

I can see the rational behind sum([])=0and prod([])=1. It's so that

sum([A,[]],2)=sum(A,2)+sum([])prod([A,[]],2)=prod(A,2)*prod([])

I do not see the rationale behind the originally posted relationship, though. Taking a slightly different example, I can see perhaps that

ones(3,0)*ones(0,3)

should end up being 3x3 because of the outer dimensions, but why should it end up containing zeros.